Various fabric surface modifying agents have been commercialized and are currently used in detergent compositions and fabric softener/antistatic articles and compositions. Examples of surface modifying agents are soil release polymers. Soil release polymers typically comprise an oligomeric or polymeric ester "backbone" and are generally very effective on polyester or other synthetic fabrics where the grease or similar hydrophobic stains form an attached film and are not easily removed in an aqueous laundering process. The soil release polymers have a less dramatic effect on "blended" fabrics, that is, on fabrics that comprise a mixture of cotton and synthetic material, and have little or no effect on cotton articles.
Extensive research in this area has yielded significant improvements in the effectiveness of polyester soil release agents yielding materials with enhanced product performance and capability of being incorporated into detergent formulations. Modifications of the polymer backbone as well as the selection of proper end-capping groups have produced a wide variety of polyester soil release polymers. For example, end-cap modifications, such as the use of sulfoaryl moieties and especially the low cost isethionate-derived end-capping units, have increased the range of solubility and adjunct ingredient compatibility of these polymers without sacrifice to soil release effectiveness. Many polyester soil release polymers can now be formulated into both liquid as well as solid (i.e., granular) detergents.
As in the case of polyester soil release agents, producing an oligomeric or polymeric material that mimics the structure of cotton has not resulted in a cotton soil release polymer. Although cotton and polyester fabric are both comprised of long chain polymeric materials, they are chemically very different. Cotton is comprised of cellulose fibers that consist of anhydroglucose units joined by 1-4 linkages. These glycosidic linkages characterize the cotton cellulose as a polysaccharide whereas polyester soil release polymers are generally a combination of terephthalate and ethylene/propylene oxide residues. These differences in composition account for the difference in the fabric properties of cotton versus polyester fabric. Cotton is hydrophilic relative to polyester. Polyester is hydrophobic and attracts oily or greasy dirt and can be easily "dry cleaned". Importantly, the terephthalate and ethyleneoxy/propyleneoxy backbone of polyester fabric does not contain reactive sites, such as the hydroxyl moieties of cotton, that react with stains in a different manner than synthetics. Many cotton stains become "fixed" and can only be resolved by bleaching the fabric.
Until recently, the development of effective fabric surface modifying agents for use on cotton fabrics has been elusive. Attempts by others to apply the paradigm of matching the structure of a soil release polymer with the structure of the fabric, a method successful in the polyester soil release polymer field, have nevertheless yielded marginal results when applied to other fabric surface modifying agents, especially for cotton fabrics. For example, the use of methylcellulose, a cotton polysaccharide with modified oligomeric units, proved to be more effective on polyesters than on cotton.
Additionally, detergent formulators have been faced with the task of devising products to remove a broad spectrum of soils and stains from fabrics. The varieties of soils and stains ranges within a spectrum spanning from polar soils, such as proteinaceous, clay, and inorganic soils, to non-polar soils, such as soot, carbon-black, by-products of incomplete hydrocarbon combustion, and organic soils. To that end, detergent compositions have become more complex as formulators attempt to provide products which handle all types of such soils concurrently. Formulators have been highly successful in developing traditional dispersants which are particularly useful in suspending polar, highly charged, hydrophilic particles such as clay. As yet, however, dispersants designed to disperse and suspend non-polar, hydrophobic-type soils and particulates have been more difficult to develop.
It has been surprisingly discovered that effective soil release agents for cotton articles and dispersants can be prepared from certain modified polyamines. This unexpected result has yielded compositions that are key to providing these benefits once available to only synthetic and synthetic-cotton blended fabric. However, the manner in which such modified polyamines may be included into fully formulated detergent compositions so as to retain, and preferably, improve performance has remained unresolved. Detergent compositions which contain these modified polyamines and are produced via prior art processes do not perform at the desired level of performance. Accordingly, there remains a need in the art for a detergent-making process which provides a means by which selected modified polyamines can be incorporated into fully formulated detergent compositions that have enhanced cleaning performance.